http://www.techchop.com - In this episode, Paul gives us three free and open source options for building your own iSCSI SAN storage on the cheap! Links to the software discussed are:

FreeNAS: http://freenas.org
Openfiler: http://openfiler.com
IET: http://iscsitarget.sourceforge.net

Paul's instructions for building the Ubuntu SAN can be found here: http://san.bauer-power.net